Forgive me if I say something silly... it could be that your problem is more complicated but starting with simple first:
Did you swap your orbs for mind points for your characters? - that would reset the count for the quest I think!
Also completed quests will move one screen to the left, so push your left arrow all the way to see if they are there!
If this has nothing to do with your problem, then we'll have to shout louder to call Indy here!
